Bidirectional　reflection　distribution　function　(BRDF)　is　defined　as　the　ratio　of　reflected　irradiance　to　incident　irradiance　and　it　related　to　the　roughness　and　microtopography　of　the　surface　of　materials.　In　order　to　analyze　the　scattering　characteristics　of　carbon　fiber,　we　used　BP　network　to　fitting　the　BRDF　data　To　verify　the　performance　of　the　BP　network,　we　measured　BRDF　data　at　different　incident　angles　and　different　wavelengths　by　using　the　BRDF　measuring　system　with　a　laser　scanning　microscope,　then　we　used　BP　Network　to　calculate　the　BRDF　value　based　on　the　experimental　data.　The　comparison　results　show　that　the　BP　network　has　a　better　simulation　effect　and　shorter　operation　time　than　the　five　parameter　model.　In　general,　the　BP　network　has　a　strong　generalization　ability　to　rough　surface　materials,　high　calculation　accuracy　and　good　stability.